[Python-checkins] bpo-46623: Skip two test_zlib tests on s390x (GH-31096)
vstinner
webhook-mailer at python.org
Thu Feb 24 18:32:14 EST 2022
https://github.com/python/cpython/commit/9475dc0b8d2a0db40278bbcb88a89b1265a77ec9
commit: 9475dc0b8d2a0db40278bbcb88a89b1265a77ec9
branch: main
author: Victor Stinner <vstinner at python.org>
committer: vstinner <vstinner at python.org>
date: 2022-02-25T00:32:02+01:00
summary:
bpo-46623: Skip two test_zlib tests on s390x (GH-31096)
Skip test_pair() and test_speech128() of test_zlib on s390x since
they fail if zlib uses the s390x hardware accelerator.
files:
A Misc/NEWS.d/next/Tests/2022-02-03-09-45-26.bpo-46623.vxzuhV.rst
M Lib/test/test_zlib.py
diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index 04fb4d93de45e..f20aad051da96 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -3,6 +3,7 @@
from test.support import import_helper
import binascii
import copy
+import os
import pickle
import random
import sys
@@ -18,6 +19,35 @@
hasattr(zlib.decompressobj(), "copy"),
'requires Decompress.copy()')
+# bpo-46623: On s390x, when a hardware accelerator is used, using different
+# ways to compress data with zlib can produce different compressed data.
+# Simplified test_pair() code:
+#
+# def func1(data):
+# return zlib.compress(data)
+#
+# def func2(data)
+# co = zlib.compressobj()
+# x1 = co.compress(data)
+# x2 = co.flush()
+# return x1 + x2
+#
+# On s390x if zlib uses a hardware accelerator, func1() creates a single
+# "final" compressed block whereas func2() produces 3 compressed blocks (the
+# last one is a final block). On other platforms with no accelerator, func1()
+# and func2() produce the same compressed data made of a single (final)
+# compressed block.
+#
+# Only the compressed data is different, the decompression returns the original
+# data:
+#
+# zlib.decompress(func1(data)) == zlib.decompress(func2(data)) == data
+#
+# Make the assumption that s390x always has an accelerator to simplify the skip
+# condition. Windows doesn't have os.uname() but it doesn't support s390x.
+skip_on_s390x = unittest.skipIf(hasattr(os, 'uname') and os.uname().machine == 's390x',
+ 'skipped on s390x')
+
class VersionTestCase(unittest.TestCase):
@@ -182,6 +212,7 @@ def test_keywords(self):
bufsize=zlib.DEF_BUF_SIZE),
HAMLET_SCENE)
+ @skip_on_s390x
def test_speech128(self):
# compress more data
data = HAMLET_SCENE * 128
@@ -233,6 +264,7 @@ def test_64bit_compress(self, size):
class CompressObjectTestCase(BaseCompressTestCase, unittest.TestCase):
# Test compression object
+ @skip_on_s390x
def test_pair(self):
# straightforward compress/decompress objects
datasrc = HAMLET_SCENE * 128
diff --git a/Misc/NEWS.d/next/Tests/2022-02-03-09-45-26.bpo-46623.vxzuhV.rst b/Misc/NEWS.d/next/Tests/2022-02-03-09-45-26.bpo-46623.vxzuhV.rst
new file mode 100644
index 0000000000000..be085c067a376
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2022-02-03-09-45-26.bpo-46623.vxzuhV.rst
@@ -0,0 +1,2 @@
+Skip test_pair() and test_speech128() of test_zlib on s390x since they fail
+if zlib uses the s390x hardware accelerator. Patch by Victor Stinner.
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